Episulfide compounds and stabilized polymer compositions containing same



United States Patent EPISULFIDE COMPOUNDS AND STABILIZED POLYMER COMPOSITIONS CONTAINING SAME- Milton Kosmin, Dayton, Ohio, assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. ApplicationFebruaryZQ 1 954- Serial'No. 412,945

3 Claims. (01. zen-:23)

This inventionrelates to novel-episulfide compounds which are particularly useful in stabilizing vinyl halide polymers. for stabilizing said vinyl halide polymers, and to the stable polymer compositions produced by said process.

Vinyl halide polymers may be utilized for many useful applications in industry due to their wide range of physical properties and their high resistance to oxidation, organic Solvents, acids, and alkal-ies; These polymers find application for example in'the production of-coating compositions, fibers, films, andin theproduction' of shaped articles by various molding techniques. The industrial use of these polymers is, however, considerably restricted by their tendency to decompose in the presence of heat and light with the liberation of acidic decomposition products. As a result of this decomposition, the polymers become discolored and in many instances lose many of their more desirable physical properties.

It has been proposed to stabilize vinyl halide polymers against this type of decomposition by the addition thereto of various organic and inorganic compounds, but the stabilizing efiect of such compounds has not been entirely satisfactory. Many of the suggested compounds have shown some activity in stabilizing the polymers against decomposition by heat, but have shown little or no effect in stabilizing the same polymers against decomposition caused by exposure to light, especially light that is rich in ultraviolet radiation.

I have now found a new and useful class of episulfide compounds which are, inter alia, particularly effective in increasing the resistance of vinyl halide polymers to decomposition by light. This novel class of compounds comprises aryloxypropene sulfides having the formula Epoxide compounds have been previously utilized as stabilizers for polyvinyl halide composition, but the present episulfide stabilizers are markedly more effective than the corresponding epoxide compounds.

The present episulfide compounds can be readily prepared by reaction of the corresponding epoxide compounds with a thiocyanate compound, such as sodium or potassium thiocyanate, in accordance with procedures well-known to those skilled in the art (see Journal of the American Chemical Society, 73, page 3444 (1951)). Typical episulfide compounds of the present invention which can be prepared according to this procedure are, for example, 3 phenoxy propene 1,2 sulfide, 3 (2,4,6 trimethylphenoxy)propene 1,2 sulfide, 3 (p-tertiary butylphenoxy)propeue 1,2 sulfide, 3 (2,4 dimethyl 6- tertiary-butylphenoxy)propene-l,2-sulfide, ortho-, meta-, and paratolyloxypropene-l,2-sulfides, 3-(p-cetylphenoxy)- propene-l,2-sulfide, 3-pentachlorophenoxypropene 1,2- sulfide, 3-(dinonylphenoxy)propene-l.Z-sulfide, etc. Preterred aryloxypropene sulfides are those in which the The invention also relates to a novel process of the said vinyl halides. T helmaterialsto be copolymer izedwith the vinyl halides are the polymerizable organic compounds containing at least one olefinic carbon pa'ir' C=C in the molecule, such' as' in vinyl acetate, diethyl'furna'rate, frietliyl -methacrylate, methaciyloriifi ile, acrylonitr ile'g styrene. ethylene, but-adier'ie', allyl'aleohdl, diallyl 1 ether, divinylsue'einat'e diallyl phthalate,; vinyl benzoat'e, allyl acetate',-diallyl adipate, andthe like, and mixtures thereof.

Whilethe present episulfide compounds can be suc cess fu'lly utilized-as the sole stabilizing agent in vinyl halide polymers; thes'eze p'isulfide stabilizers can also be utilized very advantageously in combination with other well-known vinyl halide stabilizers, for example, diallyl maleate, cadmium-or strontium naphthenates, bis-phenols, diphenyl thiourea', tri-(2-alkenyl)-phosphites such as trialiyl'-phosphite,--ete.- A particularly effective stabilizer. combination isone containing thepresent episulfidecom-' pounds-.aldng'with'fatty acid soaps ofgroup H -metals, such as strontium, barium, or cadmium stearates or laurates, or combinations thereof.

The proportion of stabilizer used in the present compositions will generally run between about 0.1 weight percent and about 10 weight percent, and preferably between about 0.5 weight percent and about 5 weight percent of stabilizer, based upon the total weight of composition stabilized.

Other substances which can be, and often will be, incorporated into the compositions of the present invention include substances such as solvents, e. g., hydrocarbons and/or ketones; pigments, e. g., lampblack, titanium dioxide or lead chromate; plasticizers, e. g., dibutyl phthalate, tricresyl phosphate or dioctyl phthalate, etc.

The following is an example of. the preparation of one of the episulfides of the present invention.

EXAMPLE 1 3-phenoxypropene-1,2-sulfide was prepared by dissolving 60.5 grams of potassium thiocyanate in a mixture 50 mLof water and 37.5 ml. of percent ethanol, and adding thereto 37.5 grams of 3-phenoxypropene-1,2-oxide. The liquid was stirred for 4 hours at room temperature, after which an additional 37.5 grams of 3-phenoxypropene-1,2-oxide was added. The stirring was then continued for 5 days at room temperature. At this time there was a solid precipitate at the bottom and an oily layer at the top of the liquid mixture. The oily layer was removed and dissolved in about cc. of ether. The ether solution was thoroughly washed with saturated sodium chloride solution and dried. The ether was then evaporated from the product and the product was distilled to give 3-phenoxypropene-1,2-sulfide having a boiling point of 9495/4 mm; n =1.5742; analysis: sulfur, calculated 19.2 percent, found 18.8 percent.

EXAMPLE 2 Several samples of plasticized polyvinyl chloride films were prepared, with and without various stabilizers, and evaluated in a Weathercmeter (light stability) test according to the method described in ASTM tests D-SSZ-46T V of degradation after about 100 hours, thus demonstrating a V cadmium laurate and glycidyi phenyl ether; On the other a V a hand, samp'les IV and VI, each of which contained l part byweightjof S-phenoxypropene-l,Z-Sulfide; showed no; sign of deterioration'until nearly 300hours, thus demonl of atleast 70% byweight of a vinyl halidernonorner and and E 42-42T;compositions the various test films were as set forth in the following table:

7 V Tabl V I [Sample eomposit ions,inparts byweigHtJ' r a r v 'Bao'd Glycldyl Phenoxy Polyvinyl Dioctyl Laurates Phenyl Propene; a Sample Chloride Phthalate' (Stabi- Ether 'Emsulfide-l (Polymer) (Plasticizer) lizer) (sitar); (Stabilizer) r a V a V 1 zor r 7 10b 1 50 100- 50 100 50 100 50 100 50 1pc so Samoles' I, II, III; and V all-showed appreciable signs the complete lack of stabilizer-acti0n;of barium" and startingrthe outstanding stabilizing activity of the episulfides of the present invention. 7 f' 1 lclaimz 1 7' ti 1. A composition of matter comprising (1) a polymer from 0 mamby weightaof a polyinerizable organic compound; containing at least one olefinic carbon pair Q-' -'C and (2) between about'0.5% by weight and polymer; of an aryloxy'propened,2-sulfide.

, 4 about 10%"by weightfbased upon the Weight of said 2. A composition of matter comprlsmg sand from 0 to 30% by weight'of a polymeri'zableorganic compound 7 containing at. least one olefinic carbon "pair JC'=C and (2) between: about0.2 %'by"weight fand.

about 5% by'weight, based upon thie weight of-s'aidfpoly- V V mer, of 3-phenoxypropene 1,2-sulfide. V 3. 'A com'positidnof matter'comprising containing at least by weight vinylchloride monomer and frorn 0 to 30% by weight of a polymerizable organic compound containing at leastione', olefinic carbon pair C= C (2) between .aboutF0.2% by :weight' and about 5% by weight, vbased upon .the. weight-of said polymer of 3-phenoxypropene 1,2-sulfide, and ('3) bei tween about-0.2% by weight andabout 5% by} weight; j

based iipon the weight of said' polymer, of a fattyacjd so'ap of a metal selectedfrom the gr'oupconsis'tingfof cadmium barium'anci 'strontiunl.

1. ReferencesCitejil in thetfile of this patent UNITED STATES WPAIENTSJ 2,193,415 Coltof L .-Mar.'12, 1 940 ,2;225,573 Tendeloo Dee. 17, 19410 v2,595,636 'Brightonletaalpu; May 6, 1952," 1,609,355 Winkler Sept. 2,1952 2,743,290

1 a ayne! 7 V of at least 70% by Weight of a vinyl chloride monomer m aipolynir 

1. A COMPOSITION OF MATTER COMPRISING (1) A POLYMER OF AT LEAST 70% BY WEIGHT OF A VINYL HALIDE MONOMER AND FROM 0 TO 30% BY WEIGHT OF A POLYMERIZABLE ORGANIC COMPOUND CONTAINING AT LEAST ONE OLEFINIC CARBON PAIR (<C=C<) AND (2) BETWEEN ABOUT 0.5% BY WEIGHT AND ABOUT 10% BY WEIGHT, BASED UPON THE WEIGHT OF SAID POLYMER, OF AN ARYLOXYPROPANE-1.2-SULFIDE. 